The present invention is related to stabilizing keels and particularly to such keels utilized for stabilizing water vehicles, particularly water skis.
The present invention was conceived to enable a novice water skier to quickly learn to ski with one or two skis. Two common problems exist for beginning skiers. The first is the difficulty most beginning skiers experience in holding the tip of the ski down during initial takeoff. The second problem is to keep the ski level and pointed toward the towing boat until enough speed is achieved to bring the ski to the water surface.
The present invention aids the novice skier in both of the above situtations. Firstly, the normally V-shaped plates assist the skier in holding the tip of the ski down. This is because the plates, at low speed, are separated and inclined to produce an upward force against the rearward ski end. Consequently, a downward force is applied to the forward ski end. Further, while the ski is moving at low speeds, the plates are held apart in the V-shaped orientation. This effectively stabilizes the ski, pointing it in the direction of the towing force. Once sufficient speed is built up, the spring allows the plates to close together and form a substantially normal keel configuration. It has also been found that the present keel structure aids in guiding the ski through high speed turns. In a turn, the blade portion facing the outside of the turn will open slightly, creating a resistance. This resistance tends to pull the ski in the direction of the turn.
U.S. Pat. No. 3,201,807 granted to G. R. Weaver on Aug. 24, 1965 discloses a ski stabilizer. This device is comprised of two interconnected keel elements. The elements are connected along the horizontal line and diverge outward and downwardly. There is no V configuration wherein the plates converge forwardly such that a centering stabilizing effect is given to the water ski. The function of Weaver's inverted V-shaped stabilizer members is to enable the skier to lean and tilt the ski laterally while still maintaining at least one of the stabilizer members in a position of substantial control. The plates are angularly separated such that the skier may turn in either direction and still maintain a substantial degree of control of the ski. This device, while most likely very useful to experienced "slalom" skiers, is not intended for the purpose of teaching and assisting novice skiers.
A different problem is recognized in the J. H. Martin, Jr. U.S. Pat. No. 3,103,673 granted on Sept. 17, 1963. Martin discloses a water ski attachment that is utilized for the purpose of stabilizing the ski when the forward end thereof is held in an upward position relative to the water surface. A hydrodynamic means is provided to increase the "tractive efficiency of the water ski during its movement through the water". The means (comprised of an angular tube arranged on the keel member so as to take water in at a lower intake end and discharge the water at an upwardly disposed end) assist in holding the rearward end of the ski in a downward position as opposed to an elevated condition of the forward end.
A somewhat similar device is disclosed in the G. H. May U.S. Pat. No. 3,089,157, granted on May 14, 1963. May, however, utilizes a tunnel shaped stabilizer that is held in a horizontal condition parallel with the bottom, water engaging surface of the attached ski. The purpose of this fin is to provide a similar degree of control to the skier while eliminating the normal blade type keel that has been known to be hazardous to swimmers and fallen skiers.
U.S. Pat. No. 3,090,978 granted on May 28, 1963 to W. H. Hanson discloses a water ski device wherein horizontally retractable stabilizing members are provided and actuated by the heel of the skier. The stabilizing devices pivot about vertical axes (perpendicular to the bottom surface of the ski) between retracted positions on the top surface of the ski to laterally extended positions wherein the extended fins may engage and provide some control in assisting the skier to move to an upright condition from a substantially submerged starting position. The laterally extending plates serve to push the forward end of the ski downward and produce a lifting moment against the rear of the ski. It thereby assists movement of the skier to an upright position. It is claimed that the device enables slalom type skiing behind relatively underpowdered boats that were previously incapable of pulling a "slalom skier" to an upright position.